1. Field of the Invention
The present invention relates to an electronic component in which a functional circuit is provided on a circuit substrate and to a manufacturing method therefor, and more specifically relates to an electronic component including an electromagnetic shield structure and to a manufacturing method therefor.
2. Description of the Related Art
To date, in order to reduce the size of electronic appliances, a method in which electronic components are mounted on a mounting substrate using flip chip bonding or the like has often been used. For example, in Japanese Unexamined Patent Application Publication No. 2005-117151, a surface acoustic wave device, which is one example of such an electronic component, is disclosed.
In the surface acoustic wave device described in Japanese Unexamined Patent Application Publication No. 2005-117151, an electrode structure that includes interdigital transducers (IDTs) is formed on a piezoelectric substrate. A functional circuit that functions as a surface acoustic wave element is realized by this electrode structure.
The electronic component described in Japanese Unexamined Patent Application Publication No. 2005-117151 is mounted by flip chip bonding on a mounting substrate. In this case, the surface of the piezoelectric substrate on which the functional circuit is formed is arranged so as to face the mounting substrate.
It is strongly required that the functional circuit of the electronic component described in Japanese Unexamined Patent Application Publication No. 2005-117151 be electromagnetically shielded. In the electronic component, the surface of the piezoelectric substrate on which the functional circuit is formed is arranged so as to face the mounting substrate. Therefore, to date, it has been necessary to form a shield member for electromagnetically shielding the functional circuit on the mounting substrate.
On the other hand, a method in which a sealing layer is formed using a resin material having conductivity so as to cover an electronic component is also known. In such a case, a functional circuit section within the electronic component can be electromagnetically shielded on the electronic component side. However, the resin material layer having conductivity has to be formed in order to achieve the electromagnetic shielding function. Therefore, there has been a problem in that the external dimensions, in particular the thickness, of the electronic component are increased.